1. Field of the Invention
The field of the invention is reciprocating pump polished rod packing seals.
2. Description of Related Art
Over 75 percent of artificially lifted producing oil wells are being produced with sucker rod pumping systems, with the sucker rod string terminating in a polished rod that extends from the well head to the atmosphere. Stuffing boxes, having packing seals about the polished rod, are utilized to prevent well fluids from escaping around the polished rod. Well fluids include corrosive hydrocarbons including salt water and natural gas.
Due to the wear and tear of the moving polished rod, the corrosiveness of some well fluids, and the pressure drop across the packing seal in the stuffing box, all stuffing boxes on sucker rod pumping systems will leak at some time, requiring the primary packing seals in conventional stuffing boxes to be replaced periodically.
U.S. Pat. No. 7,343,969 to Palmour and the inventor herein has addressed these difficulties to a substantial extent, as discussed therein. The Palmour device would benefit, however, from an enhanced ability of the secondary packing arrangement of the Palmour device to accommodate lateral movement of the polished rod, and inclination of the polished rod from vertical.
What is needed is a more simplified, unique, flexible, pressure-regulating packing unit in a unitized assembly as a replacement for any manufacturer's stuffing box in the field or on new installations, with enhanced ability to accommodate lateral movement of the polished rod and inclination of the polished rod from vertical.